(34b) Design of Resilient Supply Chain Network for COVID-19 Vaccine

With the pandemic in action, around 3 million people across 210 countries have been infected by COVID-19 [1]. The number of mortality due to COVID-19 has climbed to over 200,000. Though around 30% of the infected patients have recovered, there is no evidence that these people are protected from a second infection [2]. As a result, there has been an accelerated development of the COVID-19 vaccine. The world’s top pharmaceutical companies and research organizations are attempting to develop multiple vaccines. Vaccines would protect people against the infection and in turn reduce the transmission due to herd immunity. Though a typical vaccine takes around 10 years for approval, the COVID-19 vaccines are being vigorously developed and some of them are already in clinical trials. As of 26 April 2020, around 120 vaccine candidates are in the early stage of development and 6 are in phase 1 clinical trials. With the resources of governments, vaccine development is progressing rapidly, and a vaccine could be available in 12-18 months [3].

However, the development must be followed by the delivery of the vaccines globally. The companies working on the vaccine should consider the capacity needs and trade-offs between costs and efficiency as speed to market is critical for a successful launch. Two main concerns regarding the COVID-19 vaccine distribution are: 1) unique cold chain requirement and 2) efficient and equitable distribution. Vaccines developed must be stored between 2-8 °C throughout the supply chain. The cold chain needs will vary based on the type of the COVID-19 vaccine. Resilience is another key factor in the supply chain. The supply chain should be resilient to various disruptions due to COVID-19 such as cancelled flights, closed ports, etc.

The global COVID-19 vaccine supply chain consists of optimal allocation and resilient distribution. The allocation of vaccine is a resource allocation problem due to the inevitable scarcity of the vaccine and the allocation decisions are related to prioritizing between different subgroups and reaching the herd immunity threshold so that it would limit the impact of the pandemic. The distribution of the vaccine includes cold chain logistics. The vaccines can be distributed from fixed locations or mobile facilities. It also includes inventory management at these facilities.

In this work, we develop optimization models to allocate the predicted available doses to countries i.e. to specified priority groups by defining importance factor to location-priority group pair. After obtaining the allocation, the distribution network is optimized considering various possible disruptions in the supply chain and employing different risk mitigation strategies. The challenge lies in quantifying the supply chain resilience and using proper performance measures for optimization. Through this location-distribution optimization, we demonstrate the possibility to mitigate a global pandemic with a limited quantity of vaccine and subjected to various disruptions in the supply chain.